Again, you don't have to fix bugs that are reported, but treating it as invalid to use any compiler versions except for the exact ones that you use is just counterproductive.
The "utility" of allowing "any random build environment" is that those random build environments are the ones that exist on your user's computers, and absent a particularly good reason why it shouldn't work (like, your compiler is too old, or literally broken,) for the most part it should, and usually, it's not even that hard to make it work. Adopting practices like defaulting -Werror -Wall on and closing bugs as WONTFIX INVALID because it's not any of the blessed toolchains gains you... not sure. I guess piece of mind from having less open issues and one less flag in your CI? But it is sure to be very annoying to users who have fairly standard setups and are trying to build your software; it's pretty standard behavior to report your build failures upstream, because again, usually it does actually signal something wrong somewhere.
Developers are free to do whatever they want when releasing open source code. That doesn't mean that what they are doing is good or makes any sense. There are plenty of perfectly legal things that are utterly stupid to do, like that utterly bizarre spat between Home Assistant and NixOS.
The "utility" of allowing "any random build environment" is that those random build environments are the ones that exist on your user's computers, and absent a particularly good reason why it shouldn't work (like, your compiler is too old, or literally broken,) for the most part it should, and usually, it's not even that hard to make it work. Adopting practices like defaulting -Werror -Wall on and closing bugs as WONTFIX INVALID because it's not any of the blessed toolchains gains you... not sure. I guess piece of mind from having less open issues and one less flag in your CI? But it is sure to be very annoying to users who have fairly standard setups and are trying to build your software; it's pretty standard behavior to report your build failures upstream, because again, usually it does actually signal something wrong somewhere.
Developers are free to do whatever they want when releasing open source code. That doesn't mean that what they are doing is good or makes any sense. There are plenty of perfectly legal things that are utterly stupid to do, like that utterly bizarre spat between Home Assistant and NixOS.